Wafer polishing apparatus

ABSTRACT

Provided is a wafer polishing apparatus. The wafer polishing apparatus comprises a first polishing part and a second polishing part. The first part is disposed at a position higher than a top surface of a wafer and configured to be rotated on a first rotation axis. The second polishing part is disposed at a position lower than a bottom surface of the wafer and configured to be rotated on a second rotation axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35U.S.C. 365 to Korean Patent Application No. 10-2010-0051685(filed onJun. 1, 2010), which is hereby incorporated by reference in itsentirety.

BACKGROUND

The present disclosure relates to a wafer polishing apparatus.

Electronic components including integrated circuits (ICs), large-scaleintegration (LSI) circuits, or very large-scale integration (VLSI)circuits may be formed of a semiconductor material such as singlecrystal silicon through a process of slicing a single crystal ingot madeof silicon or a semiconductor compound into thin disk-shaped wafers(as-cut-wafers), a process of forming fine electric circuits on thewafers, and a process of cutting the wafers into semiconductor chips.Processes such as lapping, etching, and polishing are performed on anas-cut-wafer sliced from an ingot to obtain a mirror surface waferhaving a mirror surface on at least one side thereof. Thereafter, fineelectric circuits are formed on the mirror surface of the wafer throughdevice forming processes. However, until the wafer is divided intosemiconductor chips, the wafer is processed with its original disk shapebeing maintained. Cleaning, drying, and carrying may be performedbetween processing processes of the wafer. If the edge of the wafer isin a sharply-cut state or non-machined rough state while the wafer isprocessed, the edge of the wafer may be broken into fine particles dueto collision with a device or other objects, or fine contaminants may beabsorbed in the rough edge of the wafer and released and scattered in alater process. In this case, a precisely processed surface of the wafermay be contaminated, which may reduce the process yield or productquality. To prevent this, the edge of the wafer may be beveled andfinished into a mirror surface (edge polishing).

Generally, such an edge polishing process is performed as follows byusing a polishing machine including a rotatable drum and an abraderformed of a material such as a synthetic resin, a nonwoven fabric, anonwoven fabric treated with a resin, a synthetic leather, and acombination thereof. While rotating a beveled silicon wafer, the abraderis pressed against the edge of the beveled silicon wafer at apredetermined angle, and a polishing composition solution containingcolloid silica as a main component is supplied to the edge of thebeveled silicon wafer.

SUMMARY

Embodiments provide a wafer polishing apparatus for efficientlypolishing an edge part of a wafer.

In one embodiment, a wafer polishing apparatus comprises: a firstpolishing part disposed at a position higher than a top surface of awafer and configured to be rotated on a first rotation axis; and asecond polishing part disposed at a position lower than a bottom surfaceof the wafer and configured to be rotated on a second rotation axis.

In another embodiment, a wafer edge polishing apparatus comprises: afirst polishing part making direct contact with an edge part of a waferand configured to be rotated on a first rotation axis; and a secondpolishing part making direct contact with the edge part of the wafer andconfigured to be rotated on a second rotation axis.

In further another embodiment, a wafer polishing part comprises: a firstpolishing part at a lateral side of a wafer; a first driving shaftconnected to the first polishing part; and a first rotation driving partconfigured to rotate the first polishing part through the first drivingshaft, wherein an outer surface of the first polishing part is broughtinto direct contact with an edge part of the wafer.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is view illustrating an apparatus for polishing an edge part of awafer according to an embodiment.

FIG. 2 is a sectional view illustrating a wafer edge.

FIG. 3 is a plan view for explaining a wafer polishing process.

FIG. 4 is a sectional view taken along line A-C of FIG. 3.

FIG. 5 is a sectional view taken along line B-C of FIG. 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, it will be understood that when a part, achuck, a wafer, or a pad is referred to as being ‘on’ another part,chuck, wafer, or pad, it can be directly on the other part, chuck, waferor pad, or one or more intervening parts, chucks, wafers, or pads mayalso be present. Further, it will be understood that when a part, achuck, a wafer, or a pad is referred to as being ‘under’ another part,chuck, wafer, or pad, it can be directly under the other part, chuck,wafer, or pad, or one or more intervening parts, chucks, wafers, or padsmay also be present. In addition, it will also be understood that when apart, a chuck, a wafer, or a pad is referred to as being ‘between’ twoparts, chucks, wafers, or pads, it can be the only the part, chuck,wafer, or pad between the two parts, chucks, wafers, or pads, or one ormore intervening parts, chucks, wafers, or pads may also be present.Further, the reference about ‘on’ and ‘under’ each part, chuck, wafer,or pad will be made on the basis of drawings. Also, in the drawings, thesizes of elements may be exaggerated for clarity of illustration, andthe size of each element does not entirely reflect an actual size.

FIG. 1 is view illustrating an apparatus for polishing an edge part of awafer according to an embodiment. FIG. 2 is a sectional viewillustrating a wafer edge. FIG. 3 is a plan view for explaining a waferpolishing process. FIG. 4 is a sectional view taken along line A-C ofFIG. 3. FIG. 5 is a sectional view taken along line B-C of FIG. 3.

Referring to FIGS. 1 to 5, the polishing apparatus of the currentembodiment includes a first polishing unit 100, a second polishing unit200, a third polishing unit 300, a first gap adjustment unit 400, asecond gap adjustment unit 500, a third gap adjustment unit 600, and afourth gap adjustment unit 700.

As shown in FIG. 2, an edge part 13 of a wafer (W) is a peripheral partof the wafer (W). The edge part 13 may be a circumferential surface ofthe wafer (W). The edge part 13 may have a rounded shape. That is, theedge part 13 of the wafer (W) may be a rounded peripheral part of thewafer (W). The edge part 13 includes a chamfer 13A, a chamfer 13B, and atop 13C.

The chamfer 13A extends from a top surface 11 of the wafer (W). That is,the chamfer 13A is directly connected to the top surface 11 of the wafer(W). The chamfer 13A is located at an upper position of the edge part13.

The chamfer 13B extends from a bottom surface 12 of the wafer (W). Thatis, the chamfer 13B is directly connected to the bottom surface 12 ofthe wafer (W). The chamfer 13B is located at a lower position of theedge part 13.

The top 13C is located between the chamfer 13A and the chamfer 13B. Thetop 13C is connected directly to the chamfer 13A and the chamfer 13B.The top 13C extends downward from the chamfer 13A and upward from thechamfer 13B. That is, the top 13C is located at a center portion of theedge part 13. In other words, the top 13C may be the outermost part ofthe wafer (W).

As shown in FIGS. 1, 3, and 4, the first polishing unit 100 is disposedat a lateral side of the wafer (W). In detail, the first polishing unit100 may be disposed at an upper position of a lateral side of the wafer(W). The first polishing unit 100 may be used to polish an upper lateralside of the wafer (W). That is, the first polishing unit 100 may bemainly used to polish the chamfer 13A.

The first polishing unit 100 includes a first driving shaft 110, a firstpolishing part 120, and a first rotation driving part 130.

The first driving shaft 110 is disposed above the wafer (W). In detail,the first driving shaft 110 is disposed at an upper lateral side of thewafer (W). The first driving shaft 110 is disposed at a position higherthan the top surface 11 of the wafer (W). That is, the first drivingshaft 110 may be disposed at a lateral side of the wafer (W) and higherthan the top surface 11 of the wafer (W).

The first driving shaft 110 extends in a first direction. The firstdirection may correspond to a direction in which the top surface 11 ofthe wafer (W) extends. In detail, the first direction may parallel withthe top surface 11 of the wafer (W).

Torque is transmitted from the first rotation driving part 130 to thefirst polishing part 120 through the first driving shaft 110. The firstdriving shaft 110 is inserted in the first polishing part 120 and fixedto the first polishing part 120. Also, the first driving shaft 110 isfixed along a main axis of the first rotation driving part 130 for beingrotated by the first rotation driving part 130.

The first polishing part 120 is connected to the first driving shaft110. In detail, the first polishing part 120 may surround the firstdriving shaft 110. The first polishing part 120 is rotated by torquetransmitted through the first driving shaft 110.

The first polishing part 120 may be shaped like a roller. Alternatively,the first polishing part 120 may have a cylindrical shape or a diskshape. A hole is formed in the first polishing part 120 to receive thefirst driving shaft 110.

The first polishing part 120 is brought into direct contact with theedge part 13 of the wafer (W). In detail, the outer surface of the firstpolishing part 120 may be brought into direct contact with the chamfer13A. The first polishing part 120 may be rotated centered on the firstdriving shaft 110 by torque transmitted through the first driving shaft110.

That is, the first polishing part 120 is rotated on a first rotationaxis Al. The first rotation axis Al corresponds to the first drivingshaft 110. The first rotation axis Al is higher than the top surface 11of the wafer (W) and may be parallel with the top surface 11 of thewafer (W).

Alternatively, the first rotation axis Al may cross a plane extendingfrom the top surface 11 of the wafer (W).

The edge part 13 of the wafer (W) can be polished using the firstpolishing part 120. In detail, as the first polishing part 120 rotates,the first polishing part 120 may mainly polish the chamfer 13A of thewafer (W).

The first polishing part 120 includes a first polishing head 121 and afirst polishing pad 122.

The first polishing head 121 is connected to the first driving shaft110. The first polishing head 121 is rotated on the first rotation axisAl. The first polishing head 121 and the first driving shaft 110 may beformed in one piece. The first polishing head 121 may have a cylindricalshape.

The first polishing pad 122 is disposed around the first polishing head121. The first polishing pad 122 may surround the first polishing head121. The first polishing pad 122 may be brought into direct contact withthe edge part 13 of the wafer (W). The first polishing pad 122 mayinclude a nonwoven fabric and a polyurethane resin.

The first rotation driving part 130 applies torque to the firstpolishing part 120 through the first driving shaft 110. The firstrotation driving part 130 may include a device such as a motor toproduce torque.

As shown in FIGS. 1, 3, and 5, the second polishing unit 200 is disposedat another lateral side of the wafer (W). In detail, the secondpolishing unit 200 may be disposed at a lower position of a lateral sideof the wafer (W). The second polishing unit 200 may be used to polish alower lateral side of the wafer (W). That is, the second polishing unit200 may be mainly used to polish the chamfer 13B.

The second polishing unit 200 includes a second driving shaft 210, asecond polishing part 220, and a second rotation driving part 230.

The second driving shaft 210 is disposed below the wafer (W). In detail,the second driving shaft 210 is disposed at a lower lateral side of thewafer (W). The second driving shaft 210 is disposed at a position lowerthan the bottom surface 12 of the wafer (W). That is, the second drivingshaft 210 may be disposed at a lateral side of the wafer (W) and lowerthan the bottom surface 12 of the wafer (W).

The second driving shaft 210 extends in a second direction. The seconddirection may correspond to a direction in which the bottom surface 12of the wafer (W) extends. In detail, the second direction may parallelwith the bottom surface 12 of the wafer (W).

Torque is transmitted from the second rotation driving part 230 to thesecond polishing part 220 through the second driving shaft 210. Thesecond driving shaft 210 is inserted in the second polishing part 220and fixed to the second polishing part 220. Also, the second drivingshaft 210 is fixed along a main axis of the second rotation driving part230 for being rotated by the second rotation driving part 230.

The second polishing part 220 is connected to the second driving shaft210. In detail, the second polishing part 220 may surround the seconddriving shaft 210. The second polishing part 220 is rotated by torquetransmitted through the second driving shaft 210.

That is, the second polishing part 220 is rotated on a second rotationaxis A2. The second rotation axis A2 corresponds to the second drivingshaft 210. The second rotation axis A2 is lower than the bottom surface12 of the wafer (W) and may be parallel with the bottom surface 12 ofthe wafer (W).

Alternatively, the second rotation axis A2 may cross a plane extendingfrom the bottom surface 12 of the wafer (W).

The second polishing part 220 may be shaped like a roller.Alternatively, the second polishing part 220 may have a cylindricalshape or a disk shape. A hole may be formed in the second polishing part220 to receive the second driving shaft 210.

The second polishing part 220 is brought into direct contact with theedge part 13 of the wafer (W). In detail, the outer surface of thesecond polishing part 220 may be brought into direct contact with thechamfer 13B. The second polishing part 220 may be rotated centered onthe second driving shaft 210 by torque transmitted through the seconddriving shaft 210.

That is, the second polishing part 220 is rotated on the second rotationaxis A2. The second rotation axis A2 corresponds to the second drivingshaft 210. The second rotation axis A2 is lower than the bottom surface12 of the wafer (W) and may be parallel with the bottom surface 12 ofthe wafer (W).

Alternatively, the second rotation axis A2 may cross a plane extendingfrom the bottom surface 12 of the wafer (W).

The first polishing part 120 and the second polishing part 220 may berotated in the same direction or in different directions. The firstpolishing part 120 and the second polishing part 220 may be rotatedclockwise or counterclockwise.

In this way, the edge part 13 of the wafer (W) can be polished using thesecond polishing part 220. In detail, as the second polishing part 220rotates, the second polishing part 220 may mainly polish the chamfer 13Bof the wafer (W).

The second polishing part 220 includes a second polishing head 221 and asecond polishing pad 222.

The second polishing head 221 is connected to the second driving shaft210. The second polishing head 221 is rotated on the second rotationaxis A2. The second polishing head 221 and the second driving shaft 210may be formed in one piece. The second polishing head 221 may have acylindrical shape.

The second polishing pad 222 is disposed around the second polishinghead 221. The second polishing pad 222 may surround the second polishinghead 221. The second polishing pad 222 may be brought into directcontact with the edge part 13 of the wafer (W). The second polishing pad222 may include a nonwoven fabric and a polyurethane resin.

Torque is transmitted from the second rotation driving part 230 to thesecond polishing part 220 through the second driving shaft 210. Thesecond rotation driving part 230 may include a device such as a motor toproduce torque.

As shown in FIGS. 1, 3, and 5, the third polishing unit 300 is disposedat a side of the wafer (W). In detail, the third polishing unit 300 maybe disposed at a lateral side of the wafer (W). The third polishing unit300 may be used to polish a center portion of the edge part 13 of thewafer (W). That is, the third polishing unit 300 may be mainly used topolish the top 13C.

The third polishing unit 300 includes a third driving shaft 310, a thirdpolishing part 320, and a third rotation driving part 330.

The third driving shaft 310 is disposed at a side of the wafer (W). Indetail, the first driving shaft 310 is disposed at a lateral side of thewafer (W). For example, the third driving shaft 310 may be disposedbetween the top surface 11 and the bottom surface 12 of the wafer (W).That is, the third driving shaft 310 may be disposed at a lateral sideof the wafer (W) on the same level as the wafer (W). For example, theaxis of the third driving shaft 310 may be disposed between the topsurface 11 and the bottom surface 12 of the wafer (W).

The third driving shaft 310 extends in a third direction. The thirddirection may correspond to a direction in which the top surface 11 andthe bottom surface 12 of the wafer (W) extend. In detail, the thirddirection may parallel with the top surface 11 and the bottom surface 12of the wafer (W).

Torque is transmitted from the third rotation driving part 330 to thethird polishing part 320 through the third driving shaft 310. The thirddriving shaft 310 is inserted in the third polishing part 320 and fixedto the third polishing part 320. Also, the third driving shaft 310 isfixed along a main axis of the third rotation driving part 330 for beingrotated by the third rotation driving part 330.

The third polishing part 320 is connected to the third driving shaft310. In detail, the third polishing part 320 may surround the thirddriving shaft 310. The third polishing part 320 is rotated by torquetransmitted through the third driving shaft 310. A rotation axis of thethird polishing part 320 is disposed between the top surface 11 and thebottom surface 12 of the wafer (W).

The third polishing part 320 may be shaped like a roller. Alternatively,the third polishing part 320 may have a cylindrical shape or a diskshape. A hole is formed in the third polishing part 320 to receive thethird driving shaft 310.

The third polishing part 320 is brought into direct contact with theedge part 13 of the wafer (W). In detail, the outer surface of the thirdpolishing part 320 may be brought into direct contact with the top 13C.The third polishing part 320 may be rotated centered on the thirddriving shaft 310 by torque transmitted through the third driving shaft310.

That is, the third polishing part 320 is rotated on a third rotationaxis A3. The third rotation axis A3 corresponds to the third drivingshaft 310. The third rotation axis A3 may be disposed between the topsurface 11 and the bottom surface 12 of the wafer (W). The thirdrotation axis A3 may be parallel with the top surface 11 and the bottomsurface 12 of the wafer (W).

Alternatively, the third rotation axis A3 may cross planes extendingfrom the top surface 11 and the bottom surface 12 of the wafer (W).

The edge part 13 of the wafer (W) can be polished using the thirdpolishing part 320. In detail, as the third polishing part 320 rotates,the third polishing part 320 may mainly polish the top 13C of the wafer(W).

The third polishing part 320 includes a third polishing head 321 and athird polishing pad 322.

The third polishing head 321 is connected to the third driving shaft310. The third polishing head 321 is rotated on the third rotation axisA3. The third polishing head 321 and the third driving shaft 310 may beformed in one piece. The third polishing head 321 may have a cylindricalshape.

The third polishing pad 322 is disposed around the third polishing head321. The third polishing pad 322 may surround the third polishing head321. The third polishing pad 322 may be brought into direct contact withthe edge part 13 of the wafer (W). The third polishing pad 322 mayinclude a nonwoven fabric and a polyurethane resin.

Torque is transmitted from the third rotation driving part 330 to thethird polishing part 320 through the third driving shaft 310. The thirdrotation driving part 330 includes a device such as a motor to producetorque.

The first gap adjustment unit 400 moves the first polishing unit 100upward and downward. That is, the vertical position of the firstpolishing unit 100 can be varied using the first gap adjustment unit400. The first gap adjustment unit 400 is fixed to a support plate 800.The first gap adjustment unit 400 includes a fourth electric motor 410and a first screw 420.

The fourth electric motor 410 is fixed to the support plate 800 torotate the first screw 420. The fourth electric motor 410 may be astepping motor. In this case, rotation of the first screw 420 can beprecisely controlled.

The first screw 420 moves the first polishing unit 100 upward anddownward by using torque received from the fourth electric motor 410.For example, the first screw 420 may be inserted in a nut 401 connectedto the first rotation driving part 130 so as to move the first polishingunit 100 upward and downward by using torque transmitted from the fourthelectric motor 410.

In some embodiments, the polishing apparatus may further include a firstguide part 402 such as a guide rod or a guide rail so as to guide thefirst polishing unit 100 when the first polishing unit 100 is movedupward or downward by the first gap adjustment unit 400. The first guidepart 402 may be fixed to the support plate 800.

The second gap adjustment unit 500 moves the second polishing unit 200upward and downward. That is, the vertical position of the secondpolishing unit 200 can be varied using the second gap adjustment unit500. The second gap adjustment unit 500 is fixed to a support plate 800.The second gap adjustment unit 500 includes a fifth electric motor 510and a second screw 520.

The fifth electric motor 510 is fixed to the support plate 800 to rotatethe second screw 520. The fifth electric motor 510 may be a steppingmotor. In this case, rotation of the second screw 520 can be preciselycontrolled.

The second screw 520 moves the second polishing unit 200 upward anddownward by using torque transmitted from the fifth electric motor 510.For example, the second screw 520 may be inserted in a nut 501 connectedto the second rotation driving part 230 so as to move the secondpolishing unit 200 upward and downward by using torque transmitted fromthe fifth electric motor 510.

In some embodiments, the polishing apparatus may further include asecond guide part 502 such as a guide rod or a guide rail so as to guidethe second polishing unit 200 when the second polishing unit 200 ismoved upward or downward by the second gap adjustment unit 500. Thesecond guide part 502 may be fixed to the support plate 800.

The third gap adjustment unit 600 moves the third polishing unit 300horizontally. That is, the horizontal position of the third polishingunit 300 can be varied using the third gap adjustment unit 600. That is,the horizontal distance between the third polishing unit 300 and thewafer (W) can be adjusted using the third gap adjustment unit 600. Thethird gap adjustment unit 600 includes a sixth electric motor 610 and athird screw 620.

The sixth electric motor 610 rotates the third screw 620. The sixthelectric motor 610 may be a stepping motor. In this case, rotation ofthe third screw 620 can be precisely controlled.

The third screw 620 moves the third polishing unit 300 upward anddownward by using torque transmitted from the sixth electric motor 610.For example, the third screw 620 may be inserted in a nut 601 connectedto the third rotation driving part 330 so as to move the third polishingunit 300 upward and downward by using torque transmitted from the sixthelectric motor 610.

In some embodiments, the polishing apparatus may further include a thirdguide part 602 such as a guide rod or a guide rail so as to guide thethird polishing unit 300 when the third polishing unit 300 ishorizontally moved by the third gap adjustment unit 600.

Furthermore, In some embodiments, the polishing apparatus may furtherinclude a frame to support and fix the third gap adjustment unit 600.

The fourth gap adjustment unit 700 moves the support plate 800horizontally. That is, the horizontal position of the support plate 800can be varied using the fourth gap adjustment unit 700. As a result, thefirst polishing unit 100 and the second polishing unit 200 can behorizontal moved using the fourth gap adjustment unit 700. That is, thehorizontal distance between the first polishing unit 100 and the wafer(W) and the horizontal distance between the second polishing unit 200and the wafer (W) can be adjusted using the fourth gap adjustment unit700. The fourth gap adjustment unit 700 includes a seventh electricmotor 710 and a fourth screw 720.

The seventh electric motor 710 rotates the fourth screw 720. The seventhelectric motor 710 may be a stepping motor. In this case, rotation ofthe fourth screw 720 can be precisely controlled.

The fourth screw 720 moves the support plate 800 horizontally by usingtorque transmitted from the seventh electric motor 710. For example, thefourth screw 720 is inserted in a nut connected to the support plate 800so as to horizontally move the support plate 800 by using torquetransmitted from the seventh electric motor 710.

In some embodiments, the polishing apparatus may further include afourth guide part (not shown) so as to guide the support plate 800 whenthe support plate 800 is horizontally moved by the fourth gap adjustmentunit 700.

Furthermore, in some embodiments, the polishing apparatus may furtherinclude a frame (not shown) to support and fix the fourth gap adjustmentunit 700.

Furthermore, in some embodiments, the polishing apparatus may furtherinclude a wafer rotating unit (not shown) to support and rotate thewafer (W). The wafer rotating unit may hold the wafer (W) by creating avacuum and rotate the wafer (W) on a fourth rotation axis.

The first rotation axis A1 crosses the fourth rotation axis. In detail,the first rotation axis A1 may cross the fourth rotation axissubstantially at right angle. The second rotation axis A2 crosses thefourth rotation axis. In detail, the second rotation axis A2 may crossthe fourth rotation axis substantially at right angle. The thirdrotation axis A3 crosses the fourth rotation axis. In detail, the thirdrotation axis A3 may cross the fourth rotation axis substantially atright angle.

Furthermore, In some embodiments, the polishing apparatus may furtherinclude a slurry injection unit (not shown) to inject a polishing liquidsuch as slurry to the wafer (W). The slurry injection unit may injectslurry to the top surface 11 of the wafer (W). Alternatively, the slurryinjection unit may inject slurry to a contact region between the firstpolishing part 120 and the edge part 13 of the wafer (W), a contactregion between the second polishing part 220 and the edge part 13 of thewafer (W), and a contact region between the third polishing part 320 andthe edge part 13 of the wafer (W).

During a polishing process, the wafer (W) may be rotated, and the firstpolishing part 120, the second polishing part 220, and the thirdpolishing part 320 may rotated while making direct contact with thewafer (W).

In this way, the edge part 13 of the wafer (W) may be polished by thefirst polishing unit 100, the second polishing unit 200, and the thirdpolishing unit 300. In detail, the chamfer 13A may be polished by thefirst polishing part 120, the chamfer 13B may be polished by the firstrotation driving part 130, and the top 13C may be polished by the thirdpolishing part 320.

Therefore, all the chamfer 13A, the chamfer 13B, and the top 13C can bepolished through a single process by using the polishing apparatus ofthe current embodiment. That is, the edge part 13 of the wafer (W) canbe efficiently polished using the polishing apparatus to reduce processtime and cost.

The first polishing unit 100 can be freely moved in vertical andhorizontal directions by the first gap adjustment unit 400 and thefourth gap adjustment unit 700. Therefore, the chamfer 13A of the wafer(W) can be polished into a desired shape by using the first polishingunit 100.

Like the first polishing unit 100, the second polishing unit 200 can befreely moved in vertical and horizontal directions by the second gapadjustment unit 500 and the fourth gap adjustment unit 700. Therefore,the chamfer 13B of the wafer (W) can be polished into a desired shape byusing the second polishing unit 200.

The third polishing unit 300 can be freely moved by the third gapadjustment unit 600 in a horizontal direction. Therefore, the top 13C ofthe wafer (W) can be polished into a desired shape by using the thirdpolishing unit 300.

That is, the edge part 13 of the wafer (W) can be polished into adesired shape by using the polishing apparatus of the currentembodiment.

As described above, polishing of the edge part 13 of the wafer (W) canbe efficiently carried out, and the shape of the edge part 13 can becontrolled as desired by using the polishing apparatus of the currentembodiment. Therefore, high-quality wafers can be produced with reducedprocess time and cost by using the polishing apparatus of theembodiment.

The polishing apparatus of the embodiments can be used in thesemiconductor industry.

According to the embodiments, an edge part of a wafer can be polished byusing the first and second polishing parts of the wafer polishingapparatus. Particularly, since the first rotation axis is higher thanthe top surface of the wafer, a first chamfer of the edge part of thewafer can be polished using the first polishing part. In addition, sincethe second rotation axis is lower than the bottom surface of the wafer,a second chamfer of the edge part of the wafer can be polished using thesecond polishing part.

That is, both the first and second chambers can be polished using thewafer polishing apparatus of the embodiments. Furthermore, in someembodiments, the wafer polishing apparatus may include a third polishingpart configured to be rotated on a third rotation axis. In this case, atop of the edge part of the wafer can be polished using the thirdpolishing part. Therefore, all the first and second chambers and the topof the edge part of the wafer can be polished using the wafer polishingapparatus of the embodiments.

Furthermore, in some embodiments, the wafer polishing apparatus mayfurther include gap adjustment units configured to move the firstpolishing part, the second polishing part, and the third polishing part.Since the first polishing part, the second polishing part, and the thirdpolishing part can be moved, the shape of the edge part of the wafer canbe controlled as desired.

Therefore, the first and second chambers and top of the edge part of thewafer can be polished to desired shapes by using the wafer polishingapparatus of the embodiments.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A wafer polishing apparatus comprising: a first polishing partdisposed at a position higher than a top surface of a wafer andconfigured to be rotated on a first rotation axis; and a secondpolishing part disposed at a position lower than a bottom surface of thewafer and configured to be rotated on a second rotation axis.
 2. Thewafer polishing approximately according to claim 1, further comprising athird polishing part disposed at a lateral side of the wafer andconfigured to be rotated on a third rotation axis.
 3. The waferpolishing approximately according to claim 2, wherein the firstpolishing part, the second polishing part, and the third polishing partare brought into direct contact with an edge part of the wafer.
 4. Thewafer polishing approximately according to claim 3, wherein the edgepart comprises: a first chamfer extending from the top surface of thewafer; a second chamfer extending from the bottom surface of the wafer;and a top between the first and second chambers, wherein the firstpolishing part is brought into direct contact with the first chamfer,the second polishing part is brought into direct contact with the secondchamfer, and the third polishing part is brought into direct contactwith the top.
 5. The wafer polishing approximately according to claim 2,wherein the first to third polishing parts are shaped like a roller, adisk, or a cylinder.
 6. The wafer polishing approximately according toclaim 2, wherein the third rotation axis is between the top and bottomsurfaces of the wafer.
 7. The wafer polishing approximately according toclaim 1, further comprising a first gap adjustment unit configured toadjust a gap between the first polishing part and the wafer.
 8. Thewafer polishing approximately according to claim 1, further comprising asecond gap adjustment unit configured to adjust a gap between the secondpolishing part and the wafer.
 9. The wafer polishing approximatelyaccording to claim 1, wherein the wafer is rotated on a fourth rotationaxis perpendicular to the top surface of the wafer; the first rotationaxis extends in a direction crossing the fourth rotation axis; and thesecond rotation axis extends in a direction crossing the fourth rotationaxis.
 10. A wafer edge polishing apparatus comprising: a first polishingpart making direct contact with an edge part of a wafer and configuredto be rotated on a first rotation axis; and a second polishing partmaking direct contact with the edge part of the wafer and configured tobe rotated on a second rotation axis.
 11. The wafer edge polishingapparatus according to claim 10, further comprising a third polishingpart making direct contact with the edge part of the wafer andconfigured to be rotated on a third rotation axis.
 12. The wafer edgepolishing apparatus according to claim 11, wherein the first rotationaxis is higher than a top surface of the wafer, the second rotation axisis lower than a bottom surface of the wafer, and the third rotation axisis between the top and bottom surfaces of the wafers.
 13. The wafer edgepolishing apparatus according to claim 10, wherein the first rotationaxis is parallel with a top surface of the wafer, and the secondrotation axis is parallel with a bottom surface of the wafer.
 14. Thewafer edge polishing apparatus according to claim 10, wherein the firstpolishing part is disposed at an upper lateral side of the wafer, andthe second polishing part is disposed at a lower lateral side of thewafer.
 15. The wafer edge polishing apparatus according to claim 11,wherein the third polishing part is disposed at a lateral side of thewafer.
 16. The wafer edge polishing apparatus according to claim 10,wherein the first polishing part comprises: a first polishing headconfigured to be rotated on the first rotation axis; and a firstpolishing pad disposed around the first polishing head.
 17. A waferpolishing part comprising: a first polishing part at a lateral side of awafer; a first driving shaft connected to the first polishing part; anda first rotation driving part configured to rotate the first polishingpart through the first driving shaft, wherein an outer surface of thefirst polishing part is brought into direct contact with an edge part ofthe wafer.
 18. The wafer polishing apparatus according to claim 17,further comprising: a second polishing part at another lateral side ofthe wafer; a second driving shaft connected to the second polishingpart; and a second rotation driving part configured to rotate the secondpolishing part through the second driving shaft, wherein an outersurface of the second polishing part is brought into direct contact withthe edge part of the wafer.
 19. The wafer polishing apparatus accordingto claim 17, further comprising a first gap adjustment unit configuredto adjust a gap between the first polishing part and the edge part ofthe wafer by moving the first positive pressure and the first rotationdriving part.
 20. The wafer polishing apparatus according to claim 19,further comprising a second gap adjustment unit configured to move thefirst positive pressure, the first rotation driving part, and the firstgap adjustment unit.